Structural study of the α-phase of Bi4V2O11

BELLETTI, GUSTAVO; ANGELINA TAMAGNO; JUAN PABLO SÁNCHEZ; PAOLA QUAINO

Tennesee

Conferencia; 26th IUPAP Conference of Computational Physics; 2025

Oak Ridge National Laboratory

Bi4V2 O11 can be considered as an intrinsically oxygen-deficient material that constitutes the first member of the Aurivillius family, characterized by alternating bismuth-oxygen layers and perovskite-like vanadium-oxygen blocks. The α polymorph is characterized by a highly ordered framework that incorporates regions of localized disorder within its vanadium–oxygen (V–O) layers. Several models have been proposed to describe the crystal structure of the α-phase of Bi4V2O11, some derived from experimental data through Rietveld refinement and others based on theoretical approaches. Consequently, the precise structure of α-Bi4V2O11 remains speculative.Such structural ambiguity is a common feature among Aurivillius phases, such as Bi2 WO6 and δ-Bi2MoO6 which exhibit non-trivial structural complexities. In this work, a series of models derived from an experimentally determined configuration is proposed. The α-phase of Bi4 V2O11 was studied using density functional theory (DFT). A series of structures with comparable energy were identified, characterized by an equal number of oxygen vacancies per V–O layer, diverse vanadium and bismuth coordination environments, and significant variations in Bi–O and V–O bond distances. The results from these models were analyzed and compared with literature data, focusing on the simulation of X-ray diffraction patterns to assess their correspondence.